I had used the mobile phone produced by the company "au" for five years, but I canceled it. I bought a new one prodeuced by the company" Vodaphone".
There is one atrractive point to me. Vodaphone in Japan started the system of fixed sum. You can talk and send e-mail to only one person you chose as much as youy want if you add only 300yen to your monthly charge.
I think I will get used to using my new mobilephone soon.